Multi-point scanning measurement, which is effective in eliminating motion errors of the stage in on-machine profile measurement, requires multiple displacement sensors of equal pitch to measure displacements simultaneously. However, it is not easy to arrange small sensors with high alignment accuracy when applying the multi-point method at a narrow pitch. In addition, if many sensors can be arranged in parallel, improvement in measurement accuracy can be expected. Therefore, a new micro electro mechanical system (MEMS) device for straightness measurement, one that integrates 10 cantilever displacement sensors, has been proposed. This device can be expected to solve the problem involved in the multi-point method because of the characteristics of MEMS, as the semiconductor processing method can make mechanical structures with high accuracy and it can easily make the device with many identical structures. The device is designed to measure waviness less than 100 μm in height. Ten cantilevers of 11 mm length are fabricated in parallel with 1.8 mm pitch on a side of a base substrate 20 mm square. The strain induced by a displacement of the probe placed near the front edge of the cantilever is detected as a change in the resistance of the piezo resistor at the foot of the cantilever. In the fabrication process of this device, crystal anisotropic etching is performed for 12 hours to form probes 250 μm high. A new fabrication process is also proposed in which a protective process is added to prevent damage to the circuits already formed during the etching. A prototype is investigated, and it is found that the resistance value increases about 0.45% in proportion to the displacement of 100 μm. It is therefore confirmed that this device has the basic ability to detect displacement.

1. [1] D. J. Whitehouse, “Some theoretical aspects of error separation techniques in surface metrology,” J. of Physics E: Scientific Instruments, Vol.9, pp. 531-536, 1976.
2. [2] H. Tanaka and H. Sato, “Basic characteristics of straightness measurement by sequential two point method,” J. of JSME Series C, Vol.48, No.436, pp. 1930-1937, 1982 (in Japanese).
3. [3] K. Tozawa, H. Sato, and M. O-hori, “A New Method for the Measurement of the Straightness of Machine Tools and Machined Work,” ASME J. of Mechanical Design, Vol.104, No.3, pp. 587-592, 1982.
4. [4] H. Tanaka and H. Sato, “Extensive analysis and development of straightness measurement by sequential two-point method,” J. Manuf. Sci. Eng., Vol.108, No.3, pp. 176-182, 1986.
5. [5] M. Obi and S. Furukawa, “A Study of the Measuring for Straightness Using a Sequential Point Method (1st Report, The Functions of Sequential Point Methods and Theoretical Analysis of the Error),” J. of JSME Series C, Vol.57, No.542, pp. 3197-3201, 1991 (in Japanese).
6. [6] E. Okuyama and H. Ishikawa, “Generalized Two-Point Method Using Inverse Filtering for Surface Profile Measurement – Theoretical Analysis and Experimental Results for Error Propagation,” Int. J. Automation Technol., Vol.8, No.1, pp. 43-48, 2014.
7. [7] W. Gao and S. Kiyono, “On-machine profile measurement of machined surface using the combined three-point method,” JSME Int. J. Series C, Vol.40, No.2, pp. 253-259, 1997.
8. [8] C. Elster, I. Weingartner, and M. Schulz, “Coupled distance sensor systems for high-accuracy topography measurement,” Precision Engineering, Vol.30, No.1, pp. 32-38, 2006.
9. [9] I. Weingärtner and C. Elster, “System of four distance sensors for high-accuracy measurement of topography,” Precision Engineering, Vol.28, pp. 164-170, 2004.
10. [10] L. Lahousse, S. Leleu, J. David et al., “Z calibration of the LNE ultra precision coordinate measuring machine,” Proc. of the 7th EUSPEN Int. Conf., 2007.
11. [11] H. Shimizu, R. Yamashita, T. Hashiguchi, T. Miyata, and Y. Tamaru, “Square Layout Four-Point Method for Two-Dimensional Profile Measurement and Self-Calibration Method of Zero-Adjustment Error,” Int. J. Automation Technol., Vol.12, No.5, pp. 707-713, 2018.
12. [12] S. Liu, K. Watanabe, X. Chen et al., “Profile measurement of a wide-area resist surface using a multi-ball cantilever system,” Precision Engineering, Vol.33, No.1, pp. 50-55, 2009.
13. [13] H. Shimizu, T. Akiyoshi, S. Yanagihara et al., “Design of a MEMS device for scanning profile measurement with three cantilever displacement sensors,” Proc. of 12th Int. Symp. on Measurement Technology and Intelligent Instruments, No.1196, 2015.
14. [14] H. Shimizu, S. Komatsu, and Y. Tamaru, “Redesign of cantilever displacement sensor to improve sensitivity and channel separation,” Proc. of the 8th Int. Conf. on Leading Edge Manufacturing in 21st Century, D10, 1512, 2015.
15. [15] K. Murayama, Y. Tamaru, and H. Shimizu, “High sensitivity MEMS displacement sensor device for planar shape measurement by deposition of piezoelectric materials,” Proc. of 8th Int. Conf. of Asian Society for Precision Engineering and Nanotechnology, C13, 2019.
16. [16] H. Shimizu, S. Mizukami, M. Manabe et al., “Error Evaluation of Straightness Measurement Using a MEMS Device Integrating 10 Cantilever Displacement Sensors,” Proc. of 14th Int. Symp. on Measurement Technology and Intelligent Instruments, D08, 2019.
17. [17] E. Okuyama, K. Konda, and H. Ishikawa, “Surface Profile Measurement Based on the Concept of Multi-Step Division of Length,” Int. J. Automation Technol., Vol.11, No.5, pp. 716-720, 2017.
18. [18] C. S. Smith, “Piezoresistance Effect in Germanium and Silicon,” Physical Review, Vol.94, No.1, pp. 42-49, 1954.
19. [19] Y. Kanda, “Piezoresistance effect of silicon,” Sensors and Actuators A: Physical, Vol.28, Issue 2, pp. 83-91, 1991.
20. [20] A. Merlos, M. Acero et al., “TMAH/IPA anisotropic etching characteristics,” Sensors and Actuators A, Vols.37-38, pp. 737-743, 1993.
21. [21] P. M. Sarro, D. Brida, W. V. D. Vlist et al., “Effect of surfactant on surface quality of silicon microstructures etched in saturated TMAHW solutions,” Sensors and Actuators A: Physical, Vol.85, Nos.1-3, pp. 340-345, 2000.